Angle Helpers

The Orientation namespace (GS_Core::Orientation) provides angle-to-sector mapping for directional gameplay — animation direction selection, facing classification, and compass-style sector queries. It splits a full circle into N equal angular sectors and determines which sector a given angle falls into, with hysteresis to prevent rapid sector-switching at boundaries.

Used by: Paper-facing systems (gs_performer), directional input reactors (gs_unit), targeting systems (gs_interaction)

For usage guides and setup examples, see The Basics: GS_Core.

Contents

• SectionConfig Enum
• RotationDirection Enum
• Pick Struct
• API Reference
• Usage Example
• See Also

SectionConfig Enum

A reflected, editor-friendly enum selecting common sector counts and alignment modes. Two alignment modes exist per count:

• cardinal / sideAligned — sector boundaries fall on the cardinal directions; sectors straddle diagonals
• quarters / forwardAligned — sector boundaries fall on diagonals; sectors straddle cardinals

Register with GS_Core::Orientation::ReflectOrientationEnums(context) to expose these in the Inspector.

RotationDirection Enum

Controls the winding convention used when computing sector angles.

Pick Struct

Returned by all PickByAngle overloads. Contains full sector geometry for the selected sector.

Use GS_Core::Orientation::Changed(pick, prevIndex) to detect when the sector index changes between frames.

API Reference

Sector Mapping

Angle Math

Yaw and Quaternion

Reflection

Usage Example

#include <GS_Core/Utility/Math/SectionByAngle.h>

// Member field — track previous sector to enable hysteresis
int m_prevSectorIndex = -1;

// In your tick / update function:
AZ::Vector3 moveDir = GetMovementDirection();

// Get the yaw from the movement direction (Z-up world)
float yaw = GS_Core::Orientation::YawFromDir(moveDir, GS_Core::Orientation::RotationDirection::CCW);

// Map to an 8-way sector with 5-degree hysteresis
GS_Core::Orientation::Pick pick = GS_Core::Orientation::PickByAngle(
    yaw,
    GS_Core::Orientation::SectionConfig::x8_cardinal,
    m_prevSectorIndex,  // previous index for hysteresis
    5.0f                // hysteresis in degrees
);

if (GS_Core::Orientation::Changed(pick, m_prevSectorIndex))
{
    m_prevSectorIndex = pick.index;
    // React to direction change: play animation, update facing, etc.
}

See Also

For related resources:

• Core Utilities
• Framework API: GS_Core

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